The invention relates to a polymer containing an aromatic ring, more particularly a polymer containing an aromatic ring comprising a fluoroalkyl group having two or more carbon atoms as the side chains.
Compared with polymers having no aromatic rings, such as polyethylene and polypropylene, a polymer containing an aromatic ring, such as polyarylether sulfones, polyarylether ether sulfones, polyarylether ketones, polyarylether ether ketones, is high in rigidity and resistance to deformation caused by strains. On the contrary, since its primary structure is rigid, the polymer is easily cracked and broken in the case where a strain is applied. Thus, it is desired to find a polymer improved in flexibility.
Further, it has been known that the above-mentioned polymer containing an aromatic ring has a certain degree of surface water-repellency, but its surface water-repellency is not so high. As the polymer containing an aromatic ring with further improved surface water-repellency, there have been known polymers obtained by copolymerization of 4,4′-(hexafluoroisopropylidene)diphenol (or hexafluorobisphenol-A) having trifluoromethyl groups (Progress in Polymer Science, 26:3 (2001)).
However, the above-mentioned polymers containing an aromatic ring are insufficient in flexibility and need to improve in water resistance in the case of use under wet environments. Thus, a polymer containing an aromatic ring, but further improved in flexibility and surface water resistance, has been desired.